Vomiting Virus Sweeps Across Majority of U.S.

A nasty stomach bug is tearing through large swathes of the U.S. Wastewater surveillance data shows norovirus levels sitting in the “high” category nationwide, with infections now climbing particularly hard across the Northeast. The virus— dubbed the “winter vomiting disease”—has also hit hikers along Southern California’s famed Pacific Crest Trail of late, according to the Pacific Crest Trail Association. The Centers for Disease Control and Prevention recorded 1,194 outbreaks between Aug. 1 and May 7. That is down from the previous season’s 2,534 outbreaks, though health officials say current levels remain consistent with historic averages. “At the national level, norovirus is still in the HIGH category due to high concentrations over the last 21 days,” Amanda Bidwell, scientific program manager at WastewaterSCAN, said. Health experts say several strains are now circulating, including GII.17, a mutated version that has overtaken older variants and caused roughly 75 percent of U.S. outbreaks during the 2024–25 season. “The newer variant isn’t more contagious in and of itself,” infectious disease specialist Dr. Linda Yancey said. “It can spread more easily because fewer people have partial immunity to it.”